Aviation, allergies and allergy medications
The spring months bring welcome warmth but also an unwanted stowaway: seasonal allergies. In terms of fitness to fly, allergies generally fall into the category of conditions that pilots can manage without the assistance of an Aviation Medical Examiner (AME) or other physician.
Remember, however, that the swollen, boggy, nasal and sinus tissues associated with allergies are a prime configuration for ear and sinus blocks, which can be incapacitating. And just because you can go up safely doesn’t mean you can go down safely. The swelling seen in both allergies and “colds” can turn some air passages into one-way valves – expanding air can escape, but cannot be “repressurized” when descending. If the symptoms are severe enough to interfere with your ability to act as pilot-in-command, you should immobilize yourself until the symptoms have subsided.
It is similar, but not identical, to fatigue management. If you feel tired, you should ground yourself until you can get enough rest. Once rested, no medical clearance is required to return to flight status.
So what’s different with allergies? Some of the most common over-the-counter medications used to treat them can be more of a problem than the allergies themselves. The main culprit is diphenhydramine (common trade name: Benadryl®). It is one of the most widespread and commonly used drugs, both alone and in combination, and its prevalence can create a problem. Since diphenhydramine is an over-the-counter and widely available drug, most pilots don’t think it could be disqualifying. But he is.
Frequently Asked Questions
Q: What’s wrong with diphenhydramine? Diphenhydramine is a sedating antihistamine. In fact, it’s such an effective sedative that it’s used in most over-the-counter combination pain relievers (i.e. Tylenol PM®) intended for bedtime use, and it’s the only ingredient active (i.e. Zzzquil®) in most over-the-counter sleeping pills. . Although diphenhydramine does not put you to sleep, it can significantly impair your cognitive abilities, which are essential to your safety.
Q: Is diphenhydramine (Benadryl) the only allergy sedative medication? No, there are others, such as chlorpheniramine (Coricidin®) and doxylamine (found in Vicks NyQuil®). If the box warning says “May cause drowsiness” or advises the user to “take care when driving a motor vehicle or using machinery”, then the drug is NOT safe to fly.
Q: Are there any allergy medications I can take and still fly? Yes, there are a number of non-sedating antihistamines. These include loratadine (Claritin®), desloratadine (Clarinex®), and fexofenadine (Allegra®). If any of these medications control your symptoms without putting you to sleep, you can use them and continue to fly with no wait time if you have no adverse effects in an initial 48 hour ground trial for any new drug.
Q: What if I need to take diphenhydramine? For some Airmen, diphenhydramine may be the most or only effective solution. In this case, you should know that laboratory tests have shown an extremely long period of weathering associated with diphenhydramine. This is why you must wait five times the maximum pharmacological half-life (or 60 hours) before resuming flight.
Resources One of your best resources is the AME Guide’s Allergy – Antihistamine & Immunotherapy Medication page: bit.ly/30LJsF1 (PDF). It describes in detail which medications are permitted, require a withdrawal period, or are unacceptable. If you have any questions, please don’t hesitate to contact an AME or your Regional Flight Surgeon’s (RFS) office.
ADDITIONAL RESOURCES Over-the-Counter Medications You Can Take and Travel Safely bit.ly/32N7FpR Medications and Flight Brochure bit.ly/3DUiMQY FAA TV: Why is the FAA concerned about over-the-counter sleeping pills? bit.ly/373zx0T Guide for AMEs Do Not Issue-Do Not Fly (DNI-DNF) list www.faa.gov/go/dni